Multi-disk friction devices are employed in clutch and brake assemblies associated with transmissions located in a vehicle powertrain. A clutch can include a first set of plates corresponding to a driving input member and a second set of plates corresponding to a driven output member. A set of friction disks or surfaces can be supported by one or both of the first and second sets of plates to be positioned interleaved between the first and second sets of plates. The clutch can be a wet multi-plate clutch, where the plates and the disks can be lubricated for rotating with respect to one another without contact. A piston can be used to cause the first and second sets of plates to come into contact with one another thereby engaging the supported friction disk surfaces for rotary transmission of torque and speed through the driving input member to the driven output member. In a vehicle having a primary driveline for driving a first set of wheels and a secondary driveline for driving a second set of wheels, a multi-disk clutch can be operated for connecting and disconnecting the secondary driveline. When the friction disk surfaces are not engaged, the input and output members can have different rotational speeds with respect to one another. When the clutch is disengaged, relative contact between the plates and the friction disk surfaces can create drag which reduces the efficiency of the power transmission between the driving input member and the driven output member. It can be desirable to separate the plates and the friction disk surfaces when the clutch is disengaged. Clutches implementing separation devices have been disclosed in U.S. Pat. No. 8,408,375; U.S. Pat. No. 8,056,694; U.S. Pat. No. 6,886,674; U.S. Pat. No. 6,543,596; U.S. Pat. No. 6,026,944; U.S. Pat. No. 5,697,473; and U.S. Pat. No. 5,226,516.